https://leetcode.cn/problems/number-of-changing-keys/description/


class Solution {
public:
    int countKeyChanges(string s) {

        int count = 0;
        for (int i = 0; i < s.size() - 1; i++)
        {
            char ch = s[i];

            if (s[i] != s[i + 1] && s[i] != s[i + 1] + 32 && s[i] + 32 != s[i + 1])
                count++;
        }

        return count;

    }
};